Requirements for the location of movement joints in masonry are dictated by the expansion and contraction characteristics of the materials. Both the National Concrete Masonry Association (NCMA) and Brick Institute of America (BIA) publish general guidelines for joint size and spacing, but designers can exercise some control over joint location and the aesthetic impact of the joints themselves. General Guidelines To accommodate thermal and moisture movements, control joints are required in concrete masonry construction and expansion joints in clay masonry construction. Both BIA and NCMA recommend that vertical movement joints be located at points of natural stress concentration. These would include corners, offsets, openings, wall intersections, and changes in wall height and thickness. Movement joints also are needed at construction or expansion joints in the foundation, roof, and backing walls; at intersections with pilasters and columns; and at parapets. Vertical Joints In placing movement joints, the objective is to divide a wall into smaller panels of masonry that can expand and contract independently of one another. Movement joints will be less noticeable if you design the exterior elevations with joint locations in mind, rather than placing them as an afterthought in a completed design. Because they occur so frequently, window and door openings often govern movement joint placement. Horizontal Joints Horizontal expansion joints in a masonry veneer can be 3/4 inch or more in width if they include both the thickness of a steel shelf angle and the thickness of the soft joint below it. The appearance of horizontal movement joints can be minimized by changing the bond pattern or unit color for a few courses above the shelf angle to create a strong horizontal band. The visual impact of a decorative band distracts the eye from soft joints, flashing, and weeps above the shelf angle.